CA2059728A1 - Process for producing hemiketals and hemithioketals - Google Patents
Process for producing hemiketals and hemithioketalsInfo
- Publication number
- CA2059728A1 CA2059728A1 CA002059728A CA2059728A CA2059728A1 CA 2059728 A1 CA2059728 A1 CA 2059728A1 CA 002059728 A CA002059728 A CA 002059728A CA 2059728 A CA2059728 A CA 2059728A CA 2059728 A1 CA2059728 A1 CA 2059728A1
- Authority
- CA
- Canada
- Prior art keywords
- mercaptan
- compound
- alcohol
- oxetan
- producing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
- C07C45/30—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation with halogen containing compounds, e.g. hypohalogenation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C327/00—Thiocarboxylic acids
- C07C327/20—Esters of monothiocarboxylic acids
- C07C327/22—Esters of monothiocarboxylic acids having carbon atoms of esterified thiocarboxyl groups bound to hydrogen atoms or to acyclic carbon atoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
- C07C67/31—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by introduction of functional groups containing oxygen only in singly bound form
Landscapes
- Organic Chemistry (AREA)
- Chemical & Material Sciences (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
- Polyesters Or Polycarbonates (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Oxygen Or Sulfur (AREA)
- Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Ceramic Products (AREA)
- Networks Using Active Elements (AREA)
- Compounds Of Unknown Constitution (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Junction Field-Effect Transistors (AREA)
- Solid State Image Pick-Up Elements (AREA)
- Plural Heterocyclic Compounds (AREA)
Abstract
39-21(2976)A
ABSTRACT
PROCESS FOR PRODUCING HEMIKETALS AND HEMITHIOKETALS
Hemiketals and hemithioketals are produced by bringing into reactive contact an alcohol or mercaptan and an oxetan-2-one compound having the following structural formula:
ABSTRACT
PROCESS FOR PRODUCING HEMIKETALS AND HEMITHIOKETALS
Hemiketals and hemithioketals are produced by bringing into reactive contact an alcohol or mercaptan and an oxetan-2-one compound having the following structural formula:
Description
7 2 ~
-1- 39-21(2976)A
PROCESS FOR PRODUCING HEMIKETALS AND HEMITHIOKETALS
BACKGROUND OF THE INVENTION
The present invention relates to a new and useful process for producing hemiketals and hemithio-ketals. More particularly, the present invention relates to a process for producing certain hemiketals and hemithioketals useful in manufacturing alkyl 4,4,4-trifluoroacetoacetate or thioalkyl 4,4,4-trifluoroacetoacetate.
As part of their chemical structure, manyagriculturally and pharmaceutically active compounds contain at least one trifluoromethyl functional group.
The presenca of one or more such groups in the compounds contributes to the desired activity of the compounds.
In U.S. Patent No. 4,785,129, compounds of alkyl 4,4,4-trifluoro-3-oxo-butanethioates, which are also referred to as thioalkyl trifluoroacetoacetates, are disclosed, along with the fact that methyl and ethyl esters of 4,4,4-trifluoro-3-oxo-butanoic acids are commercially available compounds. It is also disclosed in that patent that such compounds are useful intermediates for the preparation of herbicidal pyridine dicarbothioates and herbicidal pyridine dicarboxylates.
In U.S. Patent No. 4,618,679, the preparation of herbicides using a 3-ketoester and suitable aldehydes as intermediates is disclosed.
Various processes for making tri~luoroaceto-acetic acid compounds are known. For example, U.K.
30 Specification 931,689 discloses the manufacture o~
fluorinated acetoacetic acid chlorides, wherein a fluorinated acetyl chloride is reacted with ketene, desirably in the presence of a suitable solvent.
-. . ~ , ~
, ~
.
-1- 39-21(2976)A
PROCESS FOR PRODUCING HEMIKETALS AND HEMITHIOKETALS
BACKGROUND OF THE INVENTION
The present invention relates to a new and useful process for producing hemiketals and hemithio-ketals. More particularly, the present invention relates to a process for producing certain hemiketals and hemithioketals useful in manufacturing alkyl 4,4,4-trifluoroacetoacetate or thioalkyl 4,4,4-trifluoroacetoacetate.
As part of their chemical structure, manyagriculturally and pharmaceutically active compounds contain at least one trifluoromethyl functional group.
The presenca of one or more such groups in the compounds contributes to the desired activity of the compounds.
In U.S. Patent No. 4,785,129, compounds of alkyl 4,4,4-trifluoro-3-oxo-butanethioates, which are also referred to as thioalkyl trifluoroacetoacetates, are disclosed, along with the fact that methyl and ethyl esters of 4,4,4-trifluoro-3-oxo-butanoic acids are commercially available compounds. It is also disclosed in that patent that such compounds are useful intermediates for the preparation of herbicidal pyridine dicarbothioates and herbicidal pyridine dicarboxylates.
In U.S. Patent No. 4,618,679, the preparation of herbicides using a 3-ketoester and suitable aldehydes as intermediates is disclosed.
Various processes for making tri~luoroaceto-acetic acid compounds are known. For example, U.K.
30 Specification 931,689 discloses the manufacture o~
fluorinated acetoacetic acid chlorides, wherein a fluorinated acetyl chloride is reacted with ketene, desirably in the presence of a suitable solvent.
-. . ~ , ~
, ~
.
-2- 39-21(2976)A
SUMMARY OF THE INVENTION
The present invention provides a new and useful process for making hemiketals and hemithioketals.
The process for producing the hemiketals or hemithioketals involves bringing into reactive contact an alcohol or mercaptan and an oxetan-2-one compound having the following formula:
~ o O -- C -Hal wherein Hal is a halogen to produca a hemiketal or hemithioketal havins khe structural formula:
OH
. I
where X is O or S and R is a lower alkyl, i.e., C1 - C12 alkyl. For best yields the mercaptan or alcohol is used in near or above stoichiometric amounts. Where mercaptan is used as a reactant, it is preferred tha~
the reaction be carried out in the presence of a catalytic amount of a tertiary amine. The preferred source of the oxetan-2-one compound is a recovered by-product resulting from the manufacture of fluorinated acetoacetic acid chloride using a process, such as that disclosed in the above-mentioned U.K. specification~
!
2~728 -3- 39-21(2976)A
.~
DETAILED DBSCRIPTION OF THE INVEN~ION
As used herein, the term S'lower alkyl" and cognates thereof, such as, "alk" etcO, refers to an alkyl moiety, straight or branched chain, having from 1 to about 12 carbon atoms.
In a known process, ketene is reacted with trifluoroacetyl halide, pre~erably trifluoroacetyl chloride, in a solvent and at a reducecl temperaturD to produce trifluoroacetoacetyl halide. The following equation depicts the reaction:
-~ CH2 = C = o + CF3 C - Hal ->
Il (ketene) ~trifluoroacetyl halide) CF3C-CH2-C -Hal ,~ 11 11 (trifluoroacetoacetyl halide) wherein Hal is a halogen, such as Cl, Br or F. Also, produced in substantial quantities in amounts of about 10% by weight in the reaction between Xetene and a trifluoroacetyl halide is a 4-halo-4 trifluoromethyl-oxetan~2-one compound having the following structural formula:
.. ~0 ,, Hal wherein Hal is a halogen, such as Cl, Br, or F. After quenching with either a lower.alcohol or mercaptan, the reaction mixture can be distilled to separate the 23~7~8 -4- 3~-21(2976)A
oxetan-2-one compound, solvent and trifluoroacetoacetate compound one from the other. Preferably, the distillation is carried out at a reduc~d pressure to minimize the production of unwanted by-products.
The oxetan 2-one compound that is recovered from the distillation operation is converted to a hemiketal or hemithioketal by reacting the same with excess lower alkyl monohydric alcohol or mercaptan, respectively. For best results, the mol ratio of alcohol or mercaptan to oxetan-2-one compound is in the order of about 5:1 to 1:1. A preferred ratio is 3.5:1 to 2.5:1. The mixture can be heated at reflux to convert the oxetan-2-one compound into a hemiketal or hemithioketal in accordance with the following illustrative equation-O C ' l l ~ RXH -I
Hal - OH
RX C CH2 C XC2H5 ~ H-Hal O
where X, R and Hal are as defined above.
The resulting product is 4/4,4-trifluoro-3-ethoxy-3-hydroxy-butanoic acid, ethyl ester, where ethanol is used as a reactant or is 4,~,4-trifluoro-3-thiomethyl-3-hydroxy-butanoic acid, methylthioester where methyl mercaptan is used as a reactant.
Preferably, the hemiketal or hemithioXetal is converted to alkyl or S-alkyl trifluoroaGetoacetate.
This can be accomplished by stripping off excess alcohol 2~728 -5- 39-21~2976)A
or mercaptan from the reaction mixture and, at the same time, cleaving off the alkoxy or thioalkyl radical from the hemiketal in the form o~ an alcohol or mercaptan.
The stripping and cleaving are carried out preferably at atmospheric pressure at a reflux ratio o~ 10:1 to 1:1, most preferably about 5:1. The operation is preferably done at or near atmospheric pressure because temperatures above about 90C are needed to crack the hemiketal to the desired alkyl or S-alkyl 4,4,4-trifluoroacetoacetate. The trifluoroacetoac0tateresulting from the conversion of the hemiketal or hemithioketal can be combined with the trifluoro-acetoacetate resulting from the reaction wherein the oxetan-2-one compound is produced as a by-product and thereafter used in the preparation of herbicidal pyridine compounds. Thus, a product previously regarded as a waste product in the manufacturing of trifluorinated acetoacetic compounds from a fluorinated acetyl halide and ketene is converted to a product useful in preparing additional guantities of trifluoroacetoacetate, thereby increa~ing significantly the overall yield of trifluoroacetoacetate by about 5-10%.
It has been found that the conversion of oxetan-2-one compound to a thioate for best results should be carried out in the presence of a catalytic amount of a tertiary amine, such as triethylamine.
catalytic amount may range from about 5-30% of the weight of mercaptan employed. The mol ratio of oxetan-2 one compound to amine can range from about 1.5:1 to0.5:1. Examples of tertiary amines us~ful in the promotion o~ th0 reaction between the oxetan-2-one compound and mercaptan include trimethylamine, triethylamine, tributylamine, tri-t butylamine/ N,N-diisopropylethylamine, ~-dimethyl-aminopyridine, 1,8-diazabicyclo(5.4.0)undec-7-ene, 1,5-diaza-bicyclo(4.3.0)non-5-ene, 1,4-diazabicyclo(2.2.2)octane.
. , , - 2~72~
SUMMARY OF THE INVENTION
The present invention provides a new and useful process for making hemiketals and hemithioketals.
The process for producing the hemiketals or hemithioketals involves bringing into reactive contact an alcohol or mercaptan and an oxetan-2-one compound having the following formula:
~ o O -- C -Hal wherein Hal is a halogen to produca a hemiketal or hemithioketal havins khe structural formula:
OH
. I
where X is O or S and R is a lower alkyl, i.e., C1 - C12 alkyl. For best yields the mercaptan or alcohol is used in near or above stoichiometric amounts. Where mercaptan is used as a reactant, it is preferred tha~
the reaction be carried out in the presence of a catalytic amount of a tertiary amine. The preferred source of the oxetan-2-one compound is a recovered by-product resulting from the manufacture of fluorinated acetoacetic acid chloride using a process, such as that disclosed in the above-mentioned U.K. specification~
!
2~728 -3- 39-21(2976)A
.~
DETAILED DBSCRIPTION OF THE INVEN~ION
As used herein, the term S'lower alkyl" and cognates thereof, such as, "alk" etcO, refers to an alkyl moiety, straight or branched chain, having from 1 to about 12 carbon atoms.
In a known process, ketene is reacted with trifluoroacetyl halide, pre~erably trifluoroacetyl chloride, in a solvent and at a reducecl temperaturD to produce trifluoroacetoacetyl halide. The following equation depicts the reaction:
-~ CH2 = C = o + CF3 C - Hal ->
Il (ketene) ~trifluoroacetyl halide) CF3C-CH2-C -Hal ,~ 11 11 (trifluoroacetoacetyl halide) wherein Hal is a halogen, such as Cl, Br or F. Also, produced in substantial quantities in amounts of about 10% by weight in the reaction between Xetene and a trifluoroacetyl halide is a 4-halo-4 trifluoromethyl-oxetan~2-one compound having the following structural formula:
.. ~0 ,, Hal wherein Hal is a halogen, such as Cl, Br, or F. After quenching with either a lower.alcohol or mercaptan, the reaction mixture can be distilled to separate the 23~7~8 -4- 3~-21(2976)A
oxetan-2-one compound, solvent and trifluoroacetoacetate compound one from the other. Preferably, the distillation is carried out at a reduc~d pressure to minimize the production of unwanted by-products.
The oxetan 2-one compound that is recovered from the distillation operation is converted to a hemiketal or hemithioketal by reacting the same with excess lower alkyl monohydric alcohol or mercaptan, respectively. For best results, the mol ratio of alcohol or mercaptan to oxetan-2-one compound is in the order of about 5:1 to 1:1. A preferred ratio is 3.5:1 to 2.5:1. The mixture can be heated at reflux to convert the oxetan-2-one compound into a hemiketal or hemithioketal in accordance with the following illustrative equation-O C ' l l ~ RXH -I
Hal - OH
RX C CH2 C XC2H5 ~ H-Hal O
where X, R and Hal are as defined above.
The resulting product is 4/4,4-trifluoro-3-ethoxy-3-hydroxy-butanoic acid, ethyl ester, where ethanol is used as a reactant or is 4,~,4-trifluoro-3-thiomethyl-3-hydroxy-butanoic acid, methylthioester where methyl mercaptan is used as a reactant.
Preferably, the hemiketal or hemithioXetal is converted to alkyl or S-alkyl trifluoroaGetoacetate.
This can be accomplished by stripping off excess alcohol 2~728 -5- 39-21~2976)A
or mercaptan from the reaction mixture and, at the same time, cleaving off the alkoxy or thioalkyl radical from the hemiketal in the form o~ an alcohol or mercaptan.
The stripping and cleaving are carried out preferably at atmospheric pressure at a reflux ratio o~ 10:1 to 1:1, most preferably about 5:1. The operation is preferably done at or near atmospheric pressure because temperatures above about 90C are needed to crack the hemiketal to the desired alkyl or S-alkyl 4,4,4-trifluoroacetoacetate. The trifluoroacetoac0tateresulting from the conversion of the hemiketal or hemithioketal can be combined with the trifluoro-acetoacetate resulting from the reaction wherein the oxetan-2-one compound is produced as a by-product and thereafter used in the preparation of herbicidal pyridine compounds. Thus, a product previously regarded as a waste product in the manufacturing of trifluorinated acetoacetic compounds from a fluorinated acetyl halide and ketene is converted to a product useful in preparing additional guantities of trifluoroacetoacetate, thereby increa~ing significantly the overall yield of trifluoroacetoacetate by about 5-10%.
It has been found that the conversion of oxetan-2-one compound to a thioate for best results should be carried out in the presence of a catalytic amount of a tertiary amine, such as triethylamine.
catalytic amount may range from about 5-30% of the weight of mercaptan employed. The mol ratio of oxetan-2 one compound to amine can range from about 1.5:1 to0.5:1. Examples of tertiary amines us~ful in the promotion o~ th0 reaction between the oxetan-2-one compound and mercaptan include trimethylamine, triethylamine, tributylamine, tri-t butylamine/ N,N-diisopropylethylamine, ~-dimethyl-aminopyridine, 1,8-diazabicyclo(5.4.0)undec-7-ene, 1,5-diaza-bicyclo(4.3.0)non-5-ene, 1,4-diazabicyclo(2.2.2)octane.
. , , - 2~72~
-6- 39-21(2g76)A
The following examples are given to more particularly illustrate the invPntion and the invention is not to be regarded as being limited thereto. All parts are given on a weight basis unless otherwise indicated.
, 2~ 7~
The following examples are given to more particularly illustrate the invPntion and the invention is not to be regarded as being limited thereto. All parts are given on a weight basis unless otherwise indicated.
, 2~ 7~
-7- 39-21(2976)A
Three parts of absolute ethanol and 1 part of 4-chloro-4-trifluoromethyl-oxetan-2-one contained in th~
low boiling distillate of the reaction product of ketene and fluorinated acetoacetic acid chloride were mixed together and heated at reflux at a t~emperature of about 100C for one hour. It was determined that the reaction product comprised about 40% by weight 4,4,4-trifluoro 3~ethoxy-3-hydroxy-butanoic acid, ethyl ester.
EXAMPL~ 2 15 Three parts of methyl mercaptan, 1 part of 4-chloro-4-trifluoromethyl-oxetan-2-one contained in the low boiling distillate of the reaction product af ketene and fluorinated acetoacetic acid chloride, and 0.2 part of triethylamine were h~ated at reflux at a temperature of about 100C for one hour. It was determined that the reaction product comprised about 40% by weight 4,4,4-trifluoro-3-ethoxy-3-hydroxy-butanoic acid, methylthioate.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modificat.ions will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. AGcordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and description set forth hereinabove but rather that the claims be const~ued as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be t.reated as equivalents thereof by those skilled in the art to whi.ch the invention pertains.
. . .
:` :
Three parts of absolute ethanol and 1 part of 4-chloro-4-trifluoromethyl-oxetan-2-one contained in th~
low boiling distillate of the reaction product of ketene and fluorinated acetoacetic acid chloride were mixed together and heated at reflux at a t~emperature of about 100C for one hour. It was determined that the reaction product comprised about 40% by weight 4,4,4-trifluoro 3~ethoxy-3-hydroxy-butanoic acid, ethyl ester.
EXAMPL~ 2 15 Three parts of methyl mercaptan, 1 part of 4-chloro-4-trifluoromethyl-oxetan-2-one contained in the low boiling distillate of the reaction product af ketene and fluorinated acetoacetic acid chloride, and 0.2 part of triethylamine were h~ated at reflux at a temperature of about 100C for one hour. It was determined that the reaction product comprised about 40% by weight 4,4,4-trifluoro-3-ethoxy-3-hydroxy-butanoic acid, methylthioate.
While the illustrative embodiments of the invention have been described with particularity, it will be understood that various other modificat.ions will be apparent to and can be readily made by those skilled in the art without departing from the spirit and scope of the invention. AGcordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and description set forth hereinabove but rather that the claims be const~ued as encompassing all the features of patentable novelty which reside in the present invention, including all features which would be t.reated as equivalents thereof by those skilled in the art to whi.ch the invention pertains.
. . .
:` :
Claims (18)
1. A process for producing a hemiketal comprising bringing into reactive contact an oxetan-2-one compound having the formula:
wherein Hal is a halogen with an alcohol to produce a hemiketal having the formula:
wherein R is a lower alkyl radical.
wherein Hal is a halogen with an alcohol to produce a hemiketal having the formula:
wherein R is a lower alkyl radical.
2. The process of Claim 1 wherein the alcohol is present in near or above stoichiometric amount.
3. The process of Claim 2 wherein the alcohol and oxetane-2-one compound are heated at reflux to produce the hemiketal.
4. The process of Claim 2 wherein the mol ratio of alcohol to oxetane-2-one compound is in the order of about 5:1 to 1.5:1.
5. The process of Claim 3 wherein the mol ratio is from 3.5:1 to 2.5:1.
-9- 39-21(2976)A
-9- 39-21(2976)A
6. The process of Claim 1 wherein the alcohol is ethanol.
7. The process of Claim 2 wherein the alcohol is ethanol.
8. The process of Claim 3 wherein the alcohol is ethanol.
9. A process for producing a hemithioketal comprising bringing into reactive contact in the presence of a catalytic amount of a tertiary amine an oxetan-2-one compound having the formula:
wherein Hal is a halogen with a mercaptan to produce a hemithioketal having the formula:
wherein R is a lower alkyl radical.
wherein Hal is a halogen with a mercaptan to produce a hemithioketal having the formula:
wherein R is a lower alkyl radical.
10. The process of Claim 9 wherein the mercaptan is present in near or above stoichiometric amount.
-10- 39-21(2976)A
-10- 39-21(2976)A
11. The process of Claim 10 wherein the mercaptan and oxetan-2-one compound are heated at reflux to produce the hemithioketal.
12. The process of Claim 9 wherein the mol ratio of mercaptan to oxetan-2-one compound is in the order of about 5:1 to 1.5:1.
13. The process of Claim 12 wherein the mol ratio of mercaptan to oxetane-2-one compound is in the order of about 3.5:1 to 2.5:1.
14. The process of Claim 9 wherein the mercaptan is methyl mercaptan.
15. The process of Claim 10 wherein the mercaptan is methyl mercaptan.
16. The process of Claim 11 wherein the mercaptan is methyl mercaptan.
17. The process of Claim 1 wherein the halogen is chlorine.
18. The process of Claim 9 wherein the halogen is chlorine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/643,294 | 1991-01-22 | ||
| US07/643,294 US5113008A (en) | 1991-01-22 | 1991-01-22 | Process for producing hemiketals and hemithioketals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2059728A1 true CA2059728A1 (en) | 1992-07-23 |
Family
ID=24580178
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002059728A Abandoned CA2059728A1 (en) | 1991-01-22 | 1992-01-21 | Process for producing hemiketals and hemithioketals |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US5113008A (en) |
| EP (1) | EP0496720B1 (en) |
| JP (1) | JP3163148B2 (en) |
| KR (1) | KR950004040B1 (en) |
| AT (1) | ATE121068T1 (en) |
| AU (1) | AU636072B2 (en) |
| CA (1) | CA2059728A1 (en) |
| DE (1) | DE69201972D1 (en) |
| DK (1) | DK0496720T3 (en) |
| ES (1) | ES2072131T3 (en) |
| HU (1) | HU209982B (en) |
| IE (1) | IE920174A1 (en) |
| IL (1) | IL100699A (en) |
| ZA (1) | ZA92431B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8575273B2 (en) | 2008-11-26 | 2013-11-05 | Schlumberger Technology Corporation | Coupling agents and compositions produced using them |
| US9403962B2 (en) | 2011-12-22 | 2016-08-02 | Schlumberger Technology Corporation | Elastomer compositions with silane functionalized silica as reinforcing fillers |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1158490B (en) * | 1960-12-17 | 1963-12-05 | Hoechst Ag | Process for the production of fluorine-containing acetoacetic acid chlorides or their solutions |
| US4618679A (en) * | 1983-08-11 | 1986-10-21 | Monsanto Company | 3,5-dicarboxylic acid esters of 2,6-bis(fluoro-alkyl)-2,6-bis(hydroxy) piperidines |
| US4647689A (en) * | 1982-07-30 | 1987-03-03 | Monsanto Company | Preparation of alkyl trifluoroacetoacetate |
| US4785129A (en) * | 1988-02-16 | 1988-11-15 | Monsanto Company | Methyl 4,4,4-trifluoro-3-oxo-butanethioate |
-
1991
- 1991-01-22 US US07/643,294 patent/US5113008A/en not_active Expired - Lifetime
-
1992
- 1992-01-19 IL IL10069992A patent/IL100699A/en not_active IP Right Cessation
- 1992-01-21 CA CA002059728A patent/CA2059728A1/en not_active Abandoned
- 1992-01-21 EP EP92870014A patent/EP0496720B1/en not_active Expired - Lifetime
- 1992-01-21 HU HU9200188A patent/HU209982B/en not_active IP Right Cessation
- 1992-01-21 KR KR1019920000793A patent/KR950004040B1/en not_active IP Right Cessation
- 1992-01-21 DE DE69201972T patent/DE69201972D1/en not_active Expired - Lifetime
- 1992-01-21 DK DK92870014.5T patent/DK0496720T3/en active
- 1992-01-21 ZA ZA92431A patent/ZA92431B/en unknown
- 1992-01-21 JP JP04813392A patent/JP3163148B2/en not_active Expired - Fee Related
- 1992-01-21 AT AT92870014T patent/ATE121068T1/en not_active IP Right Cessation
- 1992-01-21 ES ES92870014T patent/ES2072131T3/en not_active Expired - Lifetime
- 1992-01-21 IE IE017492A patent/IE920174A1/en unknown
- 1992-01-21 AU AU10348/92A patent/AU636072B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| JP3163148B2 (en) | 2001-05-08 |
| IL100699A0 (en) | 1992-09-06 |
| EP0496720A1 (en) | 1992-07-29 |
| US5113008A (en) | 1992-05-12 |
| HUT60990A (en) | 1992-11-30 |
| IL100699A (en) | 1996-09-12 |
| DE69201972D1 (en) | 1995-05-18 |
| IE920174A1 (en) | 1992-07-29 |
| AU636072B2 (en) | 1993-04-08 |
| ATE121068T1 (en) | 1995-04-15 |
| AU1034892A (en) | 1992-07-30 |
| KR920014752A (en) | 1992-08-25 |
| HU209982B (en) | 1995-01-30 |
| JPH04321645A (en) | 1992-11-11 |
| EP0496720B1 (en) | 1995-04-12 |
| HU9200188D0 (en) | 1992-05-28 |
| DK0496720T3 (en) | 1995-07-31 |
| ZA92431B (en) | 1993-03-08 |
| ES2072131T3 (en) | 1995-07-01 |
| KR950004040B1 (en) | 1995-04-22 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19950722 |